Tin pot



J. W. FREE.

Y TIN POT.

APPLICATION FILED'APR.22.1921.

1,41 5, 166. I Patented May 9, 1922.

3 SHEETS-SHEET l.

WITNESSES J. W. FREE.

.TIN POT.

APPLICATION FILED APR.22, 192s.

Patented May 9, 1922.-

asnens-suuar z.

.R W. M wiww 6 W L a H 6 E ad J. W. FREE.

TIN POT.

APPLlCATlON man APR. 22. 1921.

. Patented May 9,- 1922. 3 SHEETS-SHEET 3 l/V VENTOR W/ TNE-SS E 5 o h-EYE.

JOHN w. FREE, or WOODLAWN, rnnnsrrlvanra, assrenon ro JONES & LAUGHLIN' srnnn corlrrenr, or Prr'rssnn-GH, rnrmsYLvAnL-i, a coaroaerron or Perm;

SYLVANIA.

TIN For;

' Specification of Letters Patent.

Application filed April 22, 1921. Serial No. 463,520.

T 0 all 1072,0720 it may concern Be it known that 1, JOHN WVFREE, re-

siding at Woodlawn, in the county of Beaver and State of Pennsylvania, a citizen of the United States, have invented or discovered certaln new and useful Improvements in Tin-Pots, of which improvements the following is a specification.

In the production of tin plate it'is neces sary to cause the suitably prepared plate of steel to pass through a bath of molten tin, that it may become coated with that metal; and, in order to attain best results, it is desirable that the progress of the plate shall from the moment of entrance into the tin pot to the moment of egress be continuous or substantially so. It is further desirable that the feeding inof successive plates shall be at regular and minimum intervals of time.

The last desideratum may manifestly be best accomplished by mechanical and automatically operating means. It is to the at tainment of the'ends just indicated that my present invention is directed.

Apparatus embodying my invention is illustrated. in the accompan in drawin s.

- A I": O

Fig. I is a view in vertical section through a tin pot to which the feeding apparatus has been adapted and applied; Fig. II is a plan vlew from above drawn to smaller scale; and Flg. III is a view to larger scale, corresponding to Fig. II, and illustrating a modi fic'ation in detail. I

Referring first to Fig. I, the tin pot 1 here shown is of familiar type. In use this pot is filled, as will be understood, with a bath of tin, maintained by suitable heating means in molten condition. Upon the surface of the'bath of molten metal floats a layer of flux. lVithin the pot, beneath the surface of thetin when the pot is in use, is a guide 2, 3 for the advancing plate. The direction of advance is indicated by an arrow a. Plates successively introduced the right (as seen in Fig. 1) into the guide are caused to advance through the guide by means ofa pusher 4, which engages them frombehind, and they are carried out from the tin pot by engagement between pairs of wiping and spreading rolls 5. The pusher roll pass, and there it is engaged and thence it is carried forwar l by entrainm nt b tween the rolls,

The first feature of invention to which I direct attention concerns the pusher construction, and particularly the means whereby the pusher is caused to reciprocate, and. in the course of its reciprocation to be responsive to particular and peculiar conditions of service. The pusher 4 issubstantially arc-shaped, is carried by a weighted radial arm 6, centrally pivoted, which weighted arm is periodically swung against gravity by means of aocam 7 borne by a driven shaft 8. It; is the weight of the pusher mechanism, made effective by the proper shaping of cam 7, which is the .plate-impelling force; it is the cam 7 which properly controls the pusher in its gravital' downward movement,

and which in turn raises the pusher again I that, as cam 7 turns from the position shown in full lines in Fig. I to the position shown in dotted lines, the pusher will advance to the dotted-line position. v

It will be observed of this means of effecting pusher reciprocation that the forward drive of the pusher is not positive; the parts are not coordinated in such way that, as operation progresses, the pusher must advance. If, for fortuitous cause, resistance to plate advance increases, the pusher will'stop, even though the rolls continue to -turn. There will therefore be nolaccumulationof damaged material. And this will come about without injury to the machine. f,

The platedrivenby pusher 4- enters the pass betweenrolls 5 at a speed not "greater, than, and preferably substantially thesame as,'the speed at which rolls 5will carry the plate-onward, It will readily be perceived that, ifthe pusher carried the plate into the roll pass at a speed greater than that at which the rolls carry it forward, an undesirable tendency to buckling would be brought about; if, on the otherv hand, the pusher should not advance theplates at a speed substantially as great as that at which failure to attain the possible maximum rate of production. Such a condition asthat last indicated is-of course quiteipossiblebut ordinarily it Will be preferableto produce at maximum rate. Two factors contribute cam-shaft'8, and, the ther,the particular shaping of cam'7. The rolls and the cam shaft 8 I may be driven from a common source of power, and thus rendered interdependent inthis matterof speed; or they may .be independently driven, in which case speeds will justed.

In the shaping of; cam 7 account may be taken of something more than merely c ausing the plate to reach rolls 5 at a certain speed; The engineer will realize that this pusher must recede after it has advanced, and that while it is receding the plate which it has last delivered to rolls 5 is being carried away. In order to save time in operation it will ordinarily be found advantageous to so shape cam- 7 that the retraction of the pusher will'be at much greater speed than its advance, and further to accelerate the speed during the initial part of the advance (relatively to that during the concludingpart), to the end that each newly introduced plate be properly controlled and ad- ,shall as it begins its passage through the tin pot catch up to the preceding plate,'and' shallassume the slower speed only as it approaches rolls 5. In the machine which I have built and put into operation the pusher elis withdrawn during one eighth of a rotation of cam 7 and advances during seven 'eighths of a rotation; during the first hali of its advance the pusher moves at twice the speed at which it moves. during the second hal'li. With these comments the matter of the shaping of cam 7. and the permissible modifications of shapelwill be understood.

In the retractionot pusher 4, it ordinarily will, have to pass above a newly entering sheet. I find 1t advantageous to mount pusher l' pivotally upon arm 6,. witha cer' tam and conveniently narrow range of pivotal movement,and to provide a 'counterweight 9;; the arrangement being such that the receding pusher willreadily swing upward out of the path of plate. advance, and whe-nreleased will swing again to'normal plate pushing position relatively to its carry ing j arm '6. Such swinging aside I or the pushermay be .suitably effected byenga-ge ment with the newly entering plate, for ex ample. i a y Fig, II showsthe pot to be of suchwidth as to receive plates advancing in a plurality .of paths slde by side. There, is a separate pusher. for each path. The lower pusher of v the two shown inFig. II is in the full-line positionof Fig; I, and the upper is in the dotted-line position. The reader will ob-.

serve of the bifurcated head of the pusher that, in the case of 'the lower of the two pushers of Fig. II, it appears greatly foreshortened, whereas, inthe case of the upper,

'it appears substantially in side elevation,"

"All these features of constructionare known already "to the art; it sufiices to indicate brought to position where the advancing pusher will engage them and carry them'v forward. There 1s d sadvantage n th1s,be.- cause there 1s a scarcely avoidable'mtervalof time during which'the' plate rests partly submerged-in the tin bath. Such a pause in the movement of the plate is, apt to leave upon it an inefiaceable mark.

My apparatus provides for the mechanical; .teeding forward ofithe plate to the place where the pusher engages it. The feeding forward of the plate may be minutely timed and correlated to pusher movement, so that there is no appreciable pause in the advance of the plate, from the moment it enters until it leaves the bath in the tin pot. I

Adjacent :the rim of pot 1 is a table 11., preferably inclined toward the pot, as shown, to term a properly directed approach to the uide in the bath. On the upper surface or this table a plate to be tinned may rest, and from it the plate may be advanced, 1a

to proper position for engagement by pusher 4:. p

i Beneath the surface of table 11 (which conveniently is formed of steel 'beamsfand .is of skeleton construction, as. shown) is an slideway; T he pusher,'however, is adapted .110

to be engaged periodically from beneath by dog-i l, as the dog advances along the upper and down-grade reach or" sprocket chain '12.

By such engagement the pusher is carried downward along its slideway, until the dog, 115

receding as it rounds the lower sprocket wheel, releases the pusher and allows it to return, under the influence of its counter-I weight, to itsinitialretracted position. In

Fig. I pusher 15 is shown in full lines at the 120 lower and advanced end of tits range or movement, and in dotted lines at the upper and. retractedend. The position o't dog it in the figures is diagrammatic, in that it; is i not actually engaging pusher 15. Pusher 125 15 is as I have just said at the lower-limit oi"- its'reciprocation. But in order to show l the dogmore clearly, it appears, not engag ing the pusher as properly it does, 'but in midway position along the table. In'Fig. 13G

i II the upper of the two pushers shown is 7 plate is precisely the position inwhich pusher comes into action upon it; and, furthermore, pusher 15 brings the plate to that-critical position. at substantially the identical moment of time. when pusher 4.. comes into play. There-' such pause as to result in an'imperfect or blemished plate. T he collocation of parts to effect this end is sufficiently indicated inthe drawings and will without further explanation be under stood. The timerelationin the co-operation of the two pushers may be established by driving cam 7 and sprocket wheel 13 from a single source of power, the intervening parts being suitably proportioned. It suffices in this connection to note that in the machine of the drawings sprocket wheel 1.3 is borne by a shaft 17 driven from a shaft 18 by means of the sprocket connection 19, and it is shaft 18 which imparts rotation to cam shaft 8 also.

Table 11 is, as shown in Fig. I, sloping, and means are provided to prevent the free sliding of the plates upon table 11 in response to gravity, butat the same time to leave them fully responsive to the operation of pusher 15. I show in the drawings alternative means for accomplishing this end, and this alternative showing is-m'ade in eX- emplary manner, merely, and not with any implication that it is exhaustive. 7

Referring first to Fig. I, it will be ob served of the plate-engaging extremities of the pronged pusher 15, that each is crotchshaped, that the branches 21, 22 of the crotch diverge at a narrow angle, that the branches are pivoted one to the other and that pivotal movement is resisted by a spring 23., By such provision the operator, placing a plate on table 11 (pusher 15 beingthen retracted to the dotted-line position, Fig. I), and giving it a backward or upward edgewise motion, causes it to be caught by the spring tension noted. This spring tension is sufficient to hold the plate against the tendency of gravity to cause it to slide freely down the table, but it is not so secure, but that pusher 4;, advancing in due time, dislodges the plate and carries it forward through the tin pot. r

The alternative means, illustrated in III, are found in a magnetic device for holding the plate to the table. Two of the beams 24: of the table, made conveniently as has been said of rolled steel, and for immediate purposes made necessarily of mag-- netic material, are electrically insulated from the supporting structure. These two beams are electrically connected by a bar 25 of soft iron, around which barthe conductor tion.

2 6 of. an electric circuit is helically wound. The energizing; of this circuit causes'the beams 2st to attract magnetically a plate of steel laid on the table, audit is a matter of proportions to obtain a magnetic force suilic ient ,toovercome gravity, and yet to allow the pusher 15 to perform its intended func- Fig. II shows a tin pot to which a pluralitypof pathways for plates lead',' so that successive lines of feed are established side by side. be increased, as desired.

The instrumentalities described may be .modiiied at will, withinthe knowledge of the skilled engineer.

I claim as my invention:

1. In combination. with a tin pot of a pusher adaptedv to reciprocate vertically means for, periodically elevating saidpusher against gravity and alternately allowing it to descend by gravity, the arrangement being such that the gravitally impelled descending pusher engaginga plate from behind may impel it through the tin pot.

2. In combination with a tin pot of a pusher adapted to reciprocate vertically, a shaft bearing a cam which in the range of shaft rotation alternately raises the pusher against gravity and controls its descent under gravity and a pair of roll ,the parts so arranged that the descending pusher engaging a plate from behind advances the plate'through the tin pot and intothe pass between the rolls.

Manifestly the number of thesemay 3. In combination with a tin pot of an arm pivoted to swing in vertical plane above arm, the parts so arranged and proportioned that the ascending pusher meeting a newentering plate swings against gravity on its pivot from the path of plate advance and, passing beyond the rear end of the plate, swings under gravity to plate-pushing position.

4C. In combination with a tin pot of a grav ity impelled pusher, a pair of rolls to the pass between which a plate is by the pusher advanced and by the rotation of which an entrained plate is carried forward, and a shaft bearing a cam controlling the gravital descent of the pusher, the shape of the cam being such that as the plate advances under impulsion of the pusher to the rolls the speed of pusher advance decreases.

5. Inv combination with a tin pot and a feed table, means for advancing a plate in continuous progress across the table and through the tin pot, such means including a. pusher reciprocable upon said feed table and a second pusher reciprocablein said tin pot,

the two said pushers coordinated in their re-,

ciprooation and beingso relatively placed that the pusher last named above may in its retracted position engage from the rear a sheet when carried forward by the pusher first named in its advance to extreme forward position.

I 6. In combination with a'tin pot, a feed -table therefor, a counterweighted pusher adapted to be carried forward longitudinally of said table and to recede under gravity, and an endless dog-equipped member adaptedto travel longitudinally of said table ad jacent the path ofjsaid pusher andinits travel to engage, to carry forward and to release said pusher, I substantially scribed. 1

7; In combination with a tin pot, an inclined feed table leading thereto, means for advancing a plate down the inclined table,

7 as dea and means for restraining the advancing material from sliding freely in response to gravity, substantially as described.

8. In combination with a tin pot, an inclined feed table leading thereto, a feed I member movable longitudinally of said table,

said feed member being equipped with a spring-backed grip for material,isubstan-' tially as described. p p

9. Incombination with a tin pot, a feed table. and a pair of wiping rolls, means'for advancing a plate across said feed table and into said tin pot, a gravity impelled pusher correlated in its descent with the means last named adapted to advance an introduced plate through the pot and to the wiping rolls, the said pusher. being further correlated to'thewiping rolls and adapted to admy hand' i JOHN W. FREE.

Witnesses ROBERT CREIG TON,

W. L. PoLLooK. 

